Lurching Squareback

[crunchyinmilk]

Ok, I have 3 of these babys and 1 of them that I can actually drive right now.

It was driving fine a few weeks ago, then decided to die mid-driving - wouldn't idle for more than a couple of seconds. I found that the wire to the air sensor was broke free and fixed that... then it drove fine again all the way from Magnolia to Everett.

The next time I took it out for a run, a couple of days later, it ran pretty good for a few blocks, then began to lurch. I parked it for a couple of days, then drove it again... ran like a top for about 3 miles, then began lurching again.

Swapped air pressure regulator out with one off another square of mine (one that wasn't lurching - but still a used part). Still lurching. Went to swap the throttle control valve, but realized it was an adjustable part - so I adjusted it to match a non-lurching square. Ran like a top - drove it 20 miles city, parked, drove it 20 miles I-5 - awesome.

Went to drive it again this morning and it is lurching again!!!! It was running great just last night!

Whole tank of Chevron before the 40 miles last night. Fuel injector cleaner prior to that. Idles great. Timing is good. No exhaust smells or other clues. Oil light was flickering at stops on the 40 mile run.

Help?

[Tram]

Run it until it lurches and then check the resistance of the cylinder head temp sensor and the air temp sensor on the intake. Lurching + oil light flickering (hot engine)= too lean. Make sure your ignition timing is correct as well as the point gap first.
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Немає виправдання для війни! Я з Україною.

[crunchyinmilk]

How do I set the points on the electric distributor?

[Tram]

[crunchyinmilk]

Thanks Tram!

I ear time my VWs - the light never seems to work for me. I'll check it with the light this time.

Love your strings - I have a shrine in your honor. I will be making a fresh sacrifice on your alter when Lurch is happy again!

[Tram]

[crunchyinmilk]

Ok - I'll use the light. I gave up on it when it seemed like the light said it was right when it was running at it's worst.... I really haven't got a clue what I am doing on any of this - just stumbling through and trying not to fry too many VWs in the mean time. Fortunately, I seem to be doing alright - fixed more than I broke so far.

Thanks,
Jen (aka crunchy)

FYI: strings are what these online email things are called when they go back and forth.

[cwo4smith]

Hi - this is the closest post I've seen to my problem. 68 fastback - all original/stock - about 42K original miles... drive about 24 miles to work all OK, drive home (highway) about 8 hours later - get about half-way home and the car starts to lurch/buck... easing off the throttle and dropping into neutral sometimes gets back to normal, but generally get some bucking/lurching the rest of the trip home. I am getting a flickering green when the motor is hot (at idle), but I know my oil cooler is probably leaking a bit at the seals, but I have enough (have checked) oil. So - going to Tram's comments - if timing and point gap is OK, then what am I looking for on the head temp sensor in terms of resistance - what's indicative of "bad"?

[crunchyinmilk]

I never did get to run Trams test... I twidled around with what I believe is the throttle valve switch (noticed it was set different then another square I have) and have barely had any issues since. I don't think I fixed anything - I think my square just decided I wasn't so bad.

Still get a little of the light flickering at stop lights if I am in 1st with the clutch all the way in. Doesn't always do it, and barely when it does.

I was going to check the fuel pressure and my grounds too. I had a fuel pressure issue with a square that bow-wow had rebuilt and I guess they had installed the fuel pressure regulator straight out of the box set at almost 2x the psi. Drowned the fuel injection in gas and even dripped out the tail pipe. I am wondering if it would cause the rich running at stops if the pressure was a little too high. Also hear a lot about the main grounds torturing the sensitive fuel injection but being subtle enough that the fuel injection ends up getting blamed. Sounds like a good theory to me.

Jen

[Mauisquareback]

sounds like a bad distributor, to me, had that happen to me, would happen every now and then. i check everything and it ended up being the dist.

[thepotz]

Fuel injection depends on good intake manifold vacuum.
Leaky injector seals cause vacuum leaks and engine surging.
Replace your injector seals to keep your engine running smooth.